Sewing machine



Oct. 16 1923,

W. T. B. ROBERTS SEWING MACHINE Original Filed 17 1916 Patented (lot.16, 1923.

unites rarss VJILLIAMI THOMAS BUCKINGHAM ROBERTS, 0F LEICESTER, ENGLAND,ASSIGNOR TO.

UNITED SHOE IVIACHINERY .CO'RPOB/AT PORA'IICTN OF NEW JERSEY.

* 1,4705% Parser QFFICEQ ION, G]? EATER-SON, NEW JERSEY, A COR- snwrneMnonrnn.

Original application filed November 17, 1916, Serial No. 131,905.

Divided and this application filed June 24, 1919. Serial No. 306,475.

T 0 all 10710971412 may concern:

Be it known that I. WILLIAM T. B. Ronnnrs, a subject of theKing of GreatBritain, residing at Leicester, in the county of Leicester. England.have invented certain new and useful Improvements in. Sewing Machines;and I do hereby declare the following to be a full, clear. and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to sewing machines, particularly adapted for usein the manufacture of boots and shoes. of the type in which a thread tobe drawn through the work is passed around a hooked or barbed needle bya looper, and is especially appli cable to machines of the class knownas welt and turn shoe sewing machines.

One object of the invention is to provide an auxiliary thread take-updevice, which is combined with the usual tensionwheel device for sewingmachines of the class indicated. Accordingly, one feature of theinvention contemplates the provision in a sewing machine having stitchforming devices, of thread-handling devices including a thread tension,said tension being mounted to have an auxiliary take-up motion.

Other features of the invention consist in certain details ofconstruction and combinations of parts, the advantages of which will beobvious to those skilled in the art.

The various features of the invention are illustrated in theaccompanying drawings in which: Figure 1 is a View in side elevationpartly in section of a welt and turn Wax thread shoe sewing machineembodyingthe preferred form of the invention; F g. 2 1s a verticalsectional view of the improved thread tension, and Fig. 3 is avertical'sec tion of the thread tension taken on the line 3-3 of Fig. 2.i

The machine illustrated in the drawings is of the type illustrated anddescribed in applicants co-pending application, Serial No. 131,905,filed November 17, 1916, of which the present application constitutes adivision. This machine in addition to being provided with the usualcurved hook needle 10, looper 12, thread finger 14, work support 16, andmain take-up 18, is provided with a looper ire-threading devicecomprising a thread arm 24 and a thread clamp 26. As the thread passesto the sewingpoint it runs over a thread tension wheel 28, around athread truck 30 on the machine frame, and athread truck 32 on the maintake-up 18. A braking device is provided for the tension wheelcomprising a brake shoe 34 which at the proper times acts on a brakedrum 36 carried by a shaft 38 on which the tension wheel is mounted. Theparts above described may be and preferably are the same as thecorresponding parts of the machine illustrated and described inapplicants copending application hereinbefore referred to, to whichreference may be had for a full and complete description of theseand'other parts of the machine not fully described herein. y

wen and turn shoe sewing machines are usually provided with an auxiliarytake-up located between the thread trucks 30 and 32, but in theillustrated machine the usual auxiliary take-up is omitted, the threadarm 24 and thread clamp 26 operating in a. position 1 ordinarilyoccupied by the auxiliary take-up.

the wheel. 28 and sleeve 44. One end of the spring 42 bears against thepin 48 and the other end of the spring is fixed in a collar 51' i whichis fixedon the shaft 38. One end of 'the spring 40 is fastened toa pin52 mounted in the wheel 28 and sleeve 44, and the other end of thespring 40 is fixed in a collar 53 which is secured to the shaft 38. Withthe above construction the operation of the thread tension is asfollows: When the brake 34 is removed from the drum 36 on the shaft 38,the tension wheel 28 will move freely with the shaft and the thread canbe drawn off. When the brake is acting on the drum 36, a pull on thethread will tend to rotate the tension wheel relatively to the shaft,first against the action of the spring until the pin 52 has been movedinto contact with the end of the spring 4:2, then against the action ofboth springs 40 and 42 until the end of the slot in the tension wheelcomes into contact with the pin 48. At this time the tension wheel willmove with the brake shaft to give off thread. If slack thread is givenby the stitch forming devices while the tension wheel is held by thesprings 40 and 42, the thread will be taken up by the action of thesprings. lVith this construction the thread tension, in addi tion to itsusual operation. has a take-up motion similar to that usually producedby known forms of auxiliary take-up levers an d associated springbufi'ers.

Although the improved thread tension is of special advantage in amachine employing a looper re-threading mechanism, obviously this threadtension may be embodied in almost any type of wax thread sewing machine.

The preferred embodiment of the invention having been thus described,what is claimed as new is 1. A sewing machine having, in combination,stitch forming devices including a hook needle,.a looper, a thread arm,a positively actuated main take-up, and a thread tension mounted to havean auxiliary takeupaction.

2. A sewing machine having, in combination, stitch forming devices, atension wheel shaft, and, a tension wheel mounted to rotate with saidshaft in giving 111) thread, and also having a yielding movementrelatively to said shaft.

3. A sewing machine having, in combination, stitch forming devices, atension wheel shaft, a thread tension wheel rotatably mounted on saidshaft, and means yieldingly connecting the tension wheel to the shaft topermit a yielding rotative movement on the shaft.

4. A sewing machine having, in combination, stitch forming devices, atension wheelv shaft, a thread tension wheel rotatably mounted on saidshaft, a spring connection between the tension wheel and the shaft, andmeans for limiting the movement of thetension wheel relatively to theshaft.

11A sewing machine having, in combination, stitch forming devices, atension wheel, a shaft 011 which the tension wheel is mounted, means tocontrol the movement of the shaft to give up the thread to the stitchforming devices, and a yielding connection'between the tension wheel andshaft to permit the wheel to move relatively to the shaft and "take upthread during the sewing operation.

6. A. sewing machine having, in combination, stitch forming devices, athread tension wheel, a brake to restrain the rotation thereof, andmeans permitting a yielding rotary movement of the wheel with relationto the brake.

7. A sewing machine having, in combination, stitch forming devices, athread tension wheel mounted to have a movement under a strain on thethread, a stop for limitingsaid movement, a spring for imparting areturn take-up movement to the wheel, and a brake for restraining therotation of the wheel.

8. A sewing machine having, in combination, stitch forming devices, athread tension wheel mounted to have a movement under a strain on thethread, a spring to restrain the last portion only of said movement, aspring to impart a return take-up rotary movement to the wheel, and abrake for restraining the rotation of the wheel.

9. A sewing machine having, in combination, stitchv forming devices, athread tension wheel mounted to have a yielding movement under a strainon the thread, additional means for yieldingly restraining the lastportion only of said movement and to impart a return take-up movement tothe wheel, and a brake for restraining the rotation of the wheel.

10. A sewing machine having, in combination, stitch. forming devices,and a thread,

tension includinga tension wheel over which the thread passes on its wayfrom the supply to the stitch forming devices, said ten sion wheel beingimmovable laterally of its axi and having a take-up action.

11. A sewing machine having, in combination, stitch forming devices, athread. tension wheel mounted to have a movement under a strain on thethread, a spring to restrain the last portion only of said movement, aspring cooperating with the first mentioned spring to impart a returntakeup movement to the wheel, and a brake for restraining the rotationof the wheel.

WILLIAM THOMAS BUCKINGHAM ROBERTS.

